Any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium

Usage examples of feldspar.

Oswald Brunies, the strutting, candy-sucking teacher -- a monument will be erected to him -- to him with magnifying glass on elastic, with sticky bag in sticky coat pocket, to him who collected big stones and little stones, rare pebbles, preferably mica gneiss -- muscovy biotite -- quartz, feldspar, and hornblende, who picked up pebbles, examined them, rejected or kept them, to him the Big Playground of the Conradinum was not an abrasive stumbling block but a lasting invitation to scratch about with the tip of his shoe after nine rooster steps.

Kemjawi as a byproduct of feldspar mining, and phlogopite at Siilinjarvi from an apatite mine.

Triassic red sand, acidic volcanics, pink feldspar, green chlorite, ironstone, grit, sand and silt.

The name was taken from the Chinese mountain of Kailing, where the first kaolin, or decomposed feldspar, was found.

There was no furniture as such, only stands and cases and pedestals, likewise all of polished stone: jadeite, nephrite, agate, feldspar and onyx, glabrous gray chalcedony.

The coarse-grained friable sandstone, in which the lodges have been excavated, consists chiefly of subangular and rounded grains of quartz and feldspar with a small proportion of black particles.

And that rock is very much like lunar highlands material: basically plagioclase feldspar, a calcium-aluminum silicate.

We can also extract aluminum from plagioclase, which is a kind of feldspar you find in the highlands.

This new thermoluminescence method can aid in determining the age of limestone and other rocks, such as dolomite, quartz, fluorite, and the feldspars, which are highly thermoluminescent.

Monsieur Bianchi had patiently pushed aside masses of banal quartz, chalk or feldspar, feeling at any less banal pebble with his yellow thumbnail, lifting up his glasses and squinting because of the smoke from his maize-papered cigarette that was always in his scruffy mouth: his razorblades were as stale as his toothbrush.

Oswald Brunies, the strutting, candy-sucking teacher -- a monument will be erected to him -- to him with magnifying glass on elastic, with sticky bag in sticky coat pocket, to him who collected big stones and little stones, rare pebbles, preferably mica gneiss -- muscovy biotite -- quartz, feldspar, and hornblende, who picked up pebbles, examined them, rejected or kept them, to him the Big Playground of the Conradinum was not an abrasive stumbling block but a lasting invitation to scratch about with the tip of his shoe after nine rooster steps.

And that rock is very much like lunar highlands material: basically plagioclase feldspar, a calcium-aluminum silicate.

Austell has reason to be glad of that, for without decomposed feldspar there would be no treasure house of china clay.

In the afternoon he sat in the compound breaking ore samples with a hammer, the feldspar rich in red oxide of copper and native nuggets in whose organic lobations he purported to read news of the earth's origins, holding an extemporary lecture in geology to a small gathering who nodded and spat.

In fact, locked up in Cruithne there were also troilite, olivine, pyroxene, and feldspar -- minerals that could also serve as sources of ferrous metals when the nickel-iron was exhausted, even if their extraction was a little more complex.